Moving picture projecting machine



March 15, 1932. c. FORBERG MOVING PIQTURE PROJECTING MACHINE Filed May 18, 1929 3 Sheets-Sheet March 15, 1932. c FQRBERG 1,849,664

MOVING PICTURE PROJECTING MACHINE Filed May 18, 1929 3 Sheets-Sheet 2 March 15, 1932. Q FORBERG 1,849,664

MOVING PICTURE PROJECTING MACHINE Filed May 18, 1929 3 Sheets-Sheet a $7762 r [as fr ierg Q, 74% aw W;

l atentecl Mar. 15, 1932 PATENT CHARLES FOR/BERG, OF CHICAGO, ILLINOIS, ASSIGNOR TO HELIOS CORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE MOVING PICTURE PROJEGTING MACHINE Application filed May 18, 1929.

My invention relates generally to moving picture machines and has todo more particularly with devices for projecting upon a screen, or the like, a rapid succession of images from a moving picture film.

Recent developments in the combination of moving pictures and sound, that is, so called talking-moving pictures, have made severe the demand upon moving picture projection apparatus, and it is a general object of my invention to provide apparatus which will be especially adapted for use in the projection of talking or sound pictures.

An object of my invention is to provide mechanism for driving motion picture projection apparatus which will be .so arranged as to operate with a minimum of wear and noise.

Still another object of my invention is to provide means for actuating the intermittent drive and means for actuating the continuous drive of apparatus of the class referred to which will be unusually compact and simple in construction and accessible for quick removal as a unit from its housing or for replacement of individual parts.

A particular feature of my invention is that it comprises a main drive shaft carrying cams for actuating the intermittent film feeding mechanism, means also being carried by the same shaft for providing a continuous drive to the same film.

Many other objects and advantages of the construction herein shown and described will be obvious to those skilled in the art from the disclosure herein given.

To this end my invention consists in the novel construction, arrangement and combination of parts herein shown and described, and more particularly pointed out in the claim.

In the drawings, wherein like reference characters indicate like or corresponding parts:

1 is a vertical sectional view through a casing housing mechanism embodying my invention, certain of the apparatus being shown in side elevation;

Fig. 2 is a vertical sectional View taken through the same apparatus; and

Serial No. 364,042.

Fig. 3 is a section taken on line 3-3 of Fig. 2.

The numeral 10 indicates generally a casing for housing the major portion of the apparatus embodying my invention. This casing comprises a top wall 11, a bottom wall 12, a front wall 13, a rear wall 14 having a panel 14a hinged as at 146, a side wall 15 hinged to the front wall as at 15a and a side Wall 16. The casing 10 may be substantially similar to that of the apparatus described and claimed in the patent to Proksa No. 1,748,779, issued March 11, 1930. Arranged on the top wall 11 of the casing is a suitable bracket 20 for supporting a reel of moving picture film, this bracket carrying a plurality of rotatably journaled rollers 21 arranged in'pairs for guiding the film from a reel (not shown) into the casing 10, the top wall 11 being apertured as at 22 for the passage of film.

Preferably formed integrally with the front wall 18 is a cylindrical boss 25 which is adapted to house a plurality of lenses (not shown) in a manner well known in the art, and a focusing lever 26 is provided for moving the lenses within the casing, in a well known manner.

Hingedly mounted on the wall 14 of the casing is a door 27 and pivotally mounted in a bracket 28 secured to the outer surface of the door 27 is a latch member 30. This latch member is yieldingly urged by a spring 31 into a position where it will engage a keeper 33 formed on the wall 14. It will be readily apparent that by depressing the end of the latch member 30, the door 27 may be swung outwardly on its hinges.

lVithin the lower part of the casing 10 is provided a substantially fluid-tight casing 52 (Fig. 2) for housing power transmitting mechanism to be described. The casing 52 is substantially fluid-tight in order that the power transmitting means may be bathed in lubricant at all times and is thus enabled to operate with a minimum of wear and noise. Extending into the casing 52 from any suitable source is a shaft 45 which may be actuated by any suitable source of power such as an electric motor, or the like, disposed outside of the casing 10, and arranged on the casin 52 ma be removed as a unit if deg y j 7 slred.

Secured to the shaft 50 adjacent the lower portion thereof is a gear 55 meshing with a similar gear 56 mounted on an idler shaft 57, this idler shaft being so journaled in suit- 'able bearing members provided in the walls of the casing 52 as to be vertically slidable. Secured to the shaft 57 isa spiral gear 59 meshing with a similar gear 60 mounted on a 29 shaft 61. The shaft 61 which is parallel to the shafts 57 and 50 and is also journaled in the casing 52 carries a gear 62 which meshes with a similar gear 63 secured to a shaft 65. The shaft 65 is also parallel to the shaft 50 and is rotatably j ournaled at its ends in the casing'10. A bevel gear 66 is secured to the shaft 65 and meshes with a similar gear 67 secured to one end of a shaft 68. The shaft 68 is rotatably journaled in a bearing memher 69 projecting from and preferably integral with the wall 13 of the casing and this shaft carries a disc shutter 70, which may be of any suitable type, well known in the art, or of the type disclosed in the copending application above referred to.

Secured to the shaft 65 is a governor 72, which may be of any suitable type for controlling the rotativespeed of the shutter 7 0. If desired, the governor 7 2 may be operatively connected to suitable means for interposing a fire screen between the source of light and the film which is being fed through the machine when the speed of such film is for any reason reduced below a predetermined minimum. Such apparatus is disclosed in the copending application above referred to and need not be explained in detail here.

Secured to the shaft above the gear is a worm 75 which meshes with a worm gear 50 7 6' mounted on a shaft 77. The shaft 77 extends entirely through the casing 52 and carries on one end thereof, a sheave or pulley (not shown) which is adapted to operate, by means of a belt, or the like, a rewinding reel 55 (not shown). At its opposite end, the shaft 77 carries a take-up sprocket drum 81. A blade 83 (Fig. 1) pivotally secured to a partition member of casing 52 has an edge normally bearing against the sprocket wheel 81 for the purpose of peeling off the end of a strip of film'which may stick to the drum. A spring (not shown) may be provided for resiliently urging the blade 83 into contact with the drum 81. Cooperating with the drum 81 is a grooved roller 85 rotatably mounted on an arm 87 (Fig. 1) which is pivotally mounted on the partition member as indicated at 88' A stop 89 is formed on the arm 87 opposite the pivot 88 for limiting its movement in one direction and a coiled spring 90 normally bears against the arm 87 for retaining the rollers 85 in'cooperative relationship to the drum 81, so as to bear against a strip of film passing between the rollers 85 and drum 81. A screw 92 threaded into the wall 1 1 of the casing 10 serves as an adjustable stop for limiting the rotation of the arm 87 about its pivot away from drum 81. An arm 93 is pivotally secured to the partition member 7 8 by means of a screw 94, or other suitable means, and ro- 95. j A slot 96is provided in the bottom wall 12 of the casing'10 for the passage of film out of the casing.

The function of the arm 87 is as follows In the pro ection of sound moving pictures,

By rotating the arm 87 to the left (Fig. 1)

until it abuts against the screw 92 and the film then arranged taut-between the rollers 85 and the sprocket drum 81, obviously a loop 97 of film may be formed between the picture projecting apparatus to be described and the takeoff sprocket 81, which loop is absolutely fixed in length. It is-apparent that the length of the loop may be adjusted-within certain lim its by rotation of the screw 92, which serves as a stop for the arm 87. Of course, the roller 85 also cooperates with the sprocket drum 81 for retaining the film thereon when the machine is operating. tion of the arm 93, carrying the guide rollers 95 and 95, about thepivot 94:, the length of film between the take-off sprocket 81 and the sound reproducing mechanism (not shown) may be varied within certain limits. However, once the screw 92 and arm 93-hav'e been adjusted, the length of film between the light projecting mechanism and the sound reproducing mechanism may be absolutely fixed.

Rotatably'journaled on the rear wall 14 of the casing 10 is a shaft 100 carrying at one end thereof outside of the casing 10 a manipulating knob 101. The shaft 100 extends into the casing and is connected by suitable means (not shown) to a pivoted lever 102 arranged l to cooperate with a flange 103 secured to the spiral gear 59. Rotation of the knob 101 thus results in moving the gear 59 longitudinally on its shaft which results in rotation of the spiral gear (30 meshing with the gear 59. Such rotation of the gear 60 will be transmitted by the mechanism described above and best shown in Fig. 2 to the shutter 70. By this means the shutter may be adj usted so as to be in perfect synchronism with Furthermore, by rotatatably carries a pair of guide rollers 95 and the film. This feature is more fully shown in the copending application of David E. Gilmore, S. N. 364,564, filed May 20, 1929.

Referring now to Fig. 2, it will be seen that the shaft 50, which may be called the main s iaft, has preferably formed integrally on its upper end an enlarged portion 115 having a keyway 116 therein, and rotatably engaging the portion 115 is a bearing member 1 18 secured in the top wall 11 of casing 10, as by a screw-formed end 119. The shaft 50 extends through a longitudinal sleeve. 120 having a laterally extending annular flange 121 at the lower end thereof which is seated in a suitable cup-like bearing member 122 ournaling the shaft 50 and disposed in a casing 123. The casing 123 is closed at the top t iereof by means of a suitable cap-like member 124 which has a substantially central opening 125 therein. Annular centering devices 126 substantially similar to the centering arrang ment disclosed on the copending Proksa application above referred to are provided in the upper portion of the cap-like member 124.

I The casing 123 substantially incloses the film feeding mechanism, to be described, and has in a side wall thereof an aperture closed by a screw plug (not shown) for the introduction of oil.

Disposed in the cup-like bearin member 122 and seated on the annular fl ange 121 formed on the lower portion of the sleeve 120 is a ball bearing 132. Seated above the upper race of the ball bearing 132 and journaling the sleeve 120 is a sleeve-like bearing member 135, which engages adjacent its upper extremity, the lower race of a ball bearing 136. The ball bearing 136 is arranged with its upper race secured in the cap-like member 124 and with its lower race disposed in a worm 138.

The worm 138 is rotatably mounted on the sleeve 135 and is provided with a key 139 extending through the sleeve 135 and slidably engaging the keywav 116 in the enlarged portion 115 of the shaft 50. The worm 138 is pinned to a cam 140 by means of stud 141, the cam 140 being rotatably mounted on the sleeve 135. The cam may be of any suitable type for imparting intermittent motion to a star wheel 145 and may, if desired, be of the type described and claimed in Patent 1,170,991 dated February 8, 1915. It will be readily understood by those familiar with the art that each rotation of the cam 140 produces a rotation of 90 in the star wheel 145. The cam 140 is pinned by means of a stud 147, or the like, to a spool-like member 148 rotatably mounted on sleeve 135. Arranged on the sleeve 135 above the ball bearing 132 and having a flange 149 engageable with the upper race thereof is a cam 150 substantially similar to the cam 140 which is in operative relationship to a star wheel 151 substantially similar to the star wheel 145.

The cam 150 is pinned to a spool-like member 148 similar to spool 148 by means of a stud 147 or the like.

It may be noted at this point that, in the operation of the device, the shaft 50 carries with it the worm 138 and the sleeve 135, to which it is keyed by themember 139, the cams 140 and 150, and the spools 148 and 148, the sleeve 120 remaining substantially fixed against rotation. By means of this arrangement, the entire mechanism carried within the casing 123 by the shaft 50, and the shaft itself, may be quickly and easily replaced.

The spools 148 and 148 are adjustably secured together by means of screws 158 threaded into suitable threaded apertures in the spool 148' and through arcuate slots provided in the spool 148 in registry with said apertures. The means for adjusting the two spools relative to each other is fully described in the copending application of David E. Gilmore, above referred to, and will not be further described here. By adjusting the spools relative to each other, the cams 140 and 150 which are pinned to the respective spools and the star wheels actuated by the cams may be made to operate in perfect synchronism so that the star wheels will rotate simultaneously and the film may thus be maintained taut at all times. I

The star wheels 145 and 151 may be of any suitable type and may, if desired, be of the design described in detail in the copending Gilmore application above referred to.

Meshing with the worm 138 (Fig. 3) is a worm wheel 180 secured on a shaft 181 which is rotatably mounted in the casing 123. Secured to the other end of the shaft 181 outside of the casing 123 (Fig. 1) is a feed sprocket drum 183 which is aligned with the take-up sprocket drum 81, and cooperating with the feed sprocket drum 183 is a pair'of grooved rollers 185. These rollers are ro-- tatably mounted on arm which is carried by a bracket mounted on a wall of the casing 123' The arm is secured to the bracket in such a manner that the rollers carried thereby may be swung toward and away from the feed sprocket 183, and a spring, (not shown) is provided for retaining this lever in its extreme position. A. knurled knob 188 coaxial with the rollers 185 is provided for adjusting these rollers in relation to the sprocket drum 183. Such an arrangement for mounting the sprocket drums and rollers is clearly" described in the copending cases above referred to, and it is not considered necessary to show the same in detail.

The star wheels 145 and 151 (Fig. 2) are mounted on shafts 190 and 190' disposed inthe casing 123 and have secured to their opposite ends outside the casing 123 sprocket drums 191 and 191'. Cooperating with the sprocket drum 191 (Fig. 1) is a pair of grooved rollers 193 rotatably mounted on a bracket 195 which is pivoted to the casing 123 as at 196. A knurled knob 198 is provided for manipulating the rollers 193 about the pivot 196 and a spring (not shown) is provided for maintaining the bracket 195 in its extreme positions about its pivot 196. Similarly, a pair of grooved rollers 199 cooperate with the sprocket drum 191, the rollers 199 vided for adjusting the stripper in fixed position.

A drum 210 aligned with the sprocket drum 191 is rotatably carried by a bracket 211 which is secured to the lens holder 25. Co-

' operating with the drum 210 is a pair of fiat rollers 212 pivotally mounted on a bracket 213 which is secured to the casing 123 in a manner similar to the grooved rollers previously described. The rollers 212 may be manipulated about their pivot by means of a knurled knob 215. A helical spring 216 secured to the casing 123 by screws 217 or other suitable means is provided for maintaining a tension on the arm 213 carrying the rollers The function of the drum 210 and rollers 212 is as follows: It is impossible for the length of film between sprocket drum 191'and 191 to remain absolutely fixed, inasmuch as patches in the film will cause a constant variation. However, once the film has been arranged taut between drum 210 and sprocket drum 191, the rollers 212 will keep it so, due to their resilient mounting, whereby they will maintain the film tightly over the drum 210, so that the film will be perfectly taut and flat when passing the source of light and the alongside of the picture.

lenses and will thus provide a clear image on the screen.

Secured to the inside of the wall 15 of the casing 10 (Fig. 1) is a bracket 220 having a slot therein in which is slidable a plate 221.

The plate 221 is so arranged as to be slidable across an aperture (not shown) of a masking plate. A suitable aperture is provided in the plate 221for a pin 227 whereby the plate 221 may be adjusted in various positions with respect to the aperture of the masking plate. The object of this arrangement is to mask out the sound line of a talking film which is being projected upon the screen. If the sound line were not masked out, a wavy line of light would be projected on the screen The casing 123 is slidably j ournaled on a pair of vertically disposed pins 230 and 231 (Fig. 3) and may be raised and lowered by means comprising a lever 233 which is sesult that the picture of the film carried by.

the various sprocket drums may be properly centered V-or masked with respect to the aperture plate 221, thus preventing improper centering of the'picture on the screen.

Inasmuch as the casing 123 and the parts carried thereby are substantially centered within the casing 10 when the lever 233 is in a substantially vertical plane, a bracket 240 is secured to side wall 13 of the casing 10, projecting outwardly to serve as a stop for the lever 223. By this means, when it is desired to have access to any of the parts within the casing 10, it is only necessary to move the lever 233 about its pivot until it abuts against the stop 24:0, and the parts are then disposed in a mostadvantageous position for threading thefilm for sound pictures.

The operation of the apparatus described above will, it is believed, be clear from what has gone before. A reel containing the film which it is desired to project is arranged on the bracket 20 and the film is fed between the rollers 21, through the slot 22 in the top wall of the casing 10, is looped around a guide roller 2 10 (see Fig. 1) is fed between the feed sprocket drum 183 and its cooperating rollers 185, between the sprocket drum 191 and its cooperating rollers 193, between the drum 210 and its cooperating rollers 212, between the sprocket drum 191 and its cooperating rollers 199, betweenthe take-up sprocket drum 81 and its cooperating rollers 85, around the roller 95 mounted on the arm 93, and on out of the casing 10 through the slot 96, as clearly shown in F ig. l. The film is soarranged as to be substantially taut between the feed sprocket drums 191 and 191" and is so maintained by the rollers 212 cooperating with drum 210, in order that the picture behind the aperture plate which is being projected upon the screen may lie in substantially a single plane and the image on the screen may therefore be perfectly clear and withou' fuzziness.

After the film is arranged as shown, the 0 arm 87 carrying the rollers 85 is rotated to its limit in a counter clockwise direction (Fig. 1) so as to gauge or measure a loop of film 97 of fixed length between the feed sprocket drum 191 and the take-up sprocket drum 31, in the manner described above, in order that the length of film between the picture projecting aperture and the sound reproducing mechanism may be fixed and perfect synchronism of sound and picture may be obtained. Adjustment of this length of film may be obtained by means of the screw 92 and arm 95. The plate 221 is adjusted over the aperture in the masking plate 225 according to whether or not a sound film is being projected.

It is important to note that the film feeding sprockets are mounted on the casing 123 and are absolutely fixed in longitudinal spaced relation to each other, being carried by the casing when the same is moved by the lever 233 and parts controlled thereby for masking the picture on the screen. Hence, the length of film between the projection apparatus and the sound reproducing mechanism remains fixed at all times regardless of the masking operation and the film passing before the source of light remains taut at all times, so that a sharp image is projected. The arrangement of the motion transmitting gearing within the casing 52 efiects economy of space and enables such gears to be continually bathed in oil, thus, reducing noise and wear.

Furthermore, the arrangement of the film feeding actuating mechanism within the casing 123 is extremely advantageous inasmuch as all of the parts carried by the shaft 50 may be removed substantially as a unit or any element thereof quickly replaced or repaired. If desired, the entire shaft 50 above the coupling 5% may be removed together with all the parts carried thereby and a similar unit substituted in a very short period of time, so that the apparatus need not remain out of operation while repairs or replacements are being made. The arrangement of the worm on the shaft 50 provides a mechanism for imparting a continuous feed to the film which is greatly simplified over the devices previously use It will be readily understood, of course, that when the apparatus is in operation, the film feed sprocket drum 183, being geared directly to the worm 138, will be rotated continuously, thus maintaining a loop of fihn above the sprocket drum 191, while the sprocket drums 191 and 191 being operated by the star wheels, will be rotated intermittently. The film take-up sprocket drum 81, being geared directly to the worm 75, will also be rotated continuously.

In the claim, the term motion transmitting means will be used to indicate such mechanism as that housed within the casing 52; while the term motion converting mecha- 5 nism will refer to such elements as the cams.

Having thus described my invention, it is obvious that various immaterial modifications may be made in the same without departing from the spirit of my invention; hence I do not wish to be understood as limiting myself to the exact form, construction, arrangement and combination of parts herein shown and described, or uses mentioned.

What I claim as new and desire to secure by Letters Patent is:

In apparatus of the class described, a casing, film feeding mechanism housed within said casing, means comprising a crank arranged outside of said casing for moving said mechanism longitudinally of said casing, and means comprising a bracket projecting from a wall of said casing in the path of said crank for limiting the rotation thereof and so disposed that the rotation of said crank will be stopped when said film feeding mechanism is substantially centrally disposed within said casing.

In witness whereof, I hereunto subscribe my name this 2nd day of May, A. D., 1929.

CHARLES FORBERG. 

